Question

What is the difference between the compression ratio and cut-off ratio?

Answer 1

Answer:

$r=\dfrac{V_1}{V_2}$

$Cut\ off\ ratio \rho=\dfrac{V_3}{V_2}$

Explanation:

Generally these terms are used in diesel engine .

From the diesel cycle

in process 1-2

Compression ratio

$r=\dfrac{V_1}{V_2}$

Now for process 2-3

$\dfrac{T_3}{T_2}=\dfrac{V_3}{V_2}$

$Cut\ off\ ratio \rho=\dfrac{V_3}{V_2}$

By using these ratio efficiency of Diesel engine can be given as

Efficiency of diesel engine

$\eta =1-\dfrac{\rho ^{\gamma}-1}{r^{\gamma -1}\gamma \left (\rho -1\right )}$